SingleInitialState.h

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/*
 * This file is part of Algorithms library toolkit.
 * Copyright (C) 2017 Jan Travnicek (jan.travnicek@fit.cvut.cz)
 
 * Algorithms library toolkit is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 
 * Algorithms library toolkit is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 
 * You should have received a copy of the GNU General Public License
 * along with Algorithms library toolkit.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include <ext/algorithm>
 
#include <alib/set>
 
#include <automaton/FSM/DFA.h>
#include <automaton/FSM/NFA.h>
#include <automaton/FSM/MultiInitialStateNFA.h>
#include <automaton/FSM/MultiInitialStateEpsilonNFA.h>
#include <automaton/FSM/ExtendedNFA.h>
#include <automaton/FSM/EpsilonNFA.h>
#include <automaton/FSM/CompactNFA.h>
 
#include <label/InitialStateLabel.h>
#include <common/createUnique.hpp>
 
namespace automaton {
 
namespace simplify {
 
class SingleInitialState {
    template < class T >
    struct NFATra {
        using type = automaton::NFA < typename T::SymbolType, typename T::StateType >;
    };
 
    template < class T >
    struct EpsilonNFATra {
        using type = automaton::EpsilonNFA < typename T::SymbolType, typename T::StateType >;
    };
 
    template < class T >
    using ConvertedAutomaton = typename ext::casional <
            ext::boolean < isMultiInitialStateNFA < T > >, NFATra < T >,
            ext::boolean < isMultiInitialStateEpsilonNFA < T > >, EpsilonNFATra < T >
        >::type::type;
 
public:
    template < class T >
    requires isMultiInitialStateNFA < T > || isMultiInitialStateEpsilonNFA < T >
    static SingleInitialState::ConvertedAutomaton < T > convert ( const T & fsm );
 
    template < class T >
    requires isDFA < T > || isNFA < T > || isEpsilonNFA < T > || isExtendedNFA < T > || isCompactNFA < T >
    static T convert ( const T & fsm );
};
 
template < class T >
requires isMultiInitialStateNFA < T > || isMultiInitialStateEpsilonNFA < T >
SingleInitialState::ConvertedAutomaton < T > SingleInitialState::convert ( const T & fsm ) {
    using StateType = typename T::StateType;
 
    // step 1, 3
    StateType q0 = common::createUnique ( label::InitialStateLabel::instance < StateType > ( ), fsm.getStates ( ) );
 
    SingleInitialState::ConvertedAutomaton < T > res ( q0 );
    res.setInputAlphabet ( fsm.getInputAlphabet ( ) );
 
    for( const StateType & q : fsm.getStates ( ) )
        res.addState ( q );
 
    // step 2
    for ( const auto & q : fsm.getInitialStates ( ) )
        for(const auto & kv : fsm.getTransitionsFromState ( q ) )
            res.addTransition ( q0, kv.first.second, kv.second );
 
    for ( const auto & t : fsm.getTransitions ( ) )
        res.addTransition ( t.first.first, t.first.second, t.second );
 
    res.setFinalStates ( fsm.getFinalStates ( ) );
 
    // step 4, 5
    if ( ! ext::excludes ( fsm.getFinalStates ( ).begin ( ), fsm.getFinalStates ( ).end ( ), fsm.getInitialStates ( ).begin ( ), fsm.getInitialStates ( ).end ( ) ) )
        res.addFinalState ( q0 );
 
    return res;
}
 
template < class T >
requires isDFA < T > || isNFA < T > || isEpsilonNFA < T > || isExtendedNFA < T > || isCompactNFA < T >
T SingleInitialState::convert ( const T & fsm ) {
    return fsm;
}
 
} /* namespace simplify */
 
} /* namespace automaton */